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Biomedical subjects

J Inazawa

Publications and source records attributed to J Inazawa.

At least 199 records · Page 11Linked to original sources
PubMed1993

Expression and chromosomal assignment of PTPH1 gene encoding a cytosolic protein tyrosine phosphatase homologous to cytoskeletal-associated proteins.

We have investigated the mRNA expression of 2 human protein tyrosine phosphatases with sequence homology to cytoskeletal proteins, PTPH1 and PTPMEG. Northern-blot analysis of PTPH1 using poly (A)+ RNA from normal human colon tissue showed a low-abundance message of 4.3 kb. Reverse-transcriptase/polymerase-chain reaction (RT-PCR) was therefore used to detect it in a wide variety of cell lines including 9 colorectal, 5 gastric, 5 hepatic and 6 hematopoietic tumor cells. PTPH1 mRNA was not detected only in Colo 320 cells over-expressing c-myc mRNA, among the colorectal cancer cell lines examined. When Colo 320 cells were incubated with 5 mM sodium butyrate for 5 days, PTPH1 mRNA became detectable, concomitant with the marked decrease in the expression level of c-myc mRNA. Moreover, the chromosomal localization of PTPH1 gene was investigated by fluorescence in situ hybridization. Interestingly, PTPH1 gene was mapped to 9q31 where the gene for Gorlin syndrome, a putative tumor suppressor gene, exists.

Base Sequence↗
PubMed1993

An unspliced cDNA for human dihydrolipoamide succinyltransferase: characterization and mapping of the gene to chromosome 14q24.2-q24.3.

Abnormality of the dihydrolipoamide succinyltransferase gene may be a cause of familial Alzheimer's disease linked to chromosome 14q24.3. However, the locus of the dihydrolipoamide succinyltransferase gene on this chromosome was uncertain. An unspliced cDNA of about 2.3 kb for human dihydrolipoamide succinyltransferase was isolated. This cDNA contained three exons and four introns and the nucleotide sequences at the 5' donor and 3' acceptor sites of all introns conformed to the gt-ag rule. The amino acid sequences of the three exons support our previous observation that human dihydrolipoamide succinyltransferase lacks a sequence motif for an E1 and/or E3 binding site. The unspliced cDNA was mapped only on human chromosome 14q24.2-q24.3 by fluorescent in situ hybridization. Thus the dihydrolipoamide succinyltransferase gene is concluded to be located on human chromosome 14q24.2-q24.3.

Acyltransferases↗
PubMed1993

Detailed deletion mapping of chromosome 17q in ovarian and breast cancers: 2-cM region on 17q21.3 often and commonly deleted in tumors.

Using 11 restriction fragment length polymorphism markers, we examined loss of heterozygosity on the long arm of chromosome 17, where one or more genes responsible for hereditary breast and ovarian cancers may be present, in sporadic forms of 94 ovarian and 246 breast cancers. Loss of heterozygosity was observed in 33 of 84 (39.3%) ovarian and in 88 of 214 (41.1%) breast cancers that were informative with at least one marker. Detailed deletion mapping of chromosome 17q in these cancers identified two distinct, commonly deleted regions. One was located between 17q12 and 17q21.3 and the other between 17q25.1 and 17q25.3. In breast cancers, the proximal commonly deleted region was between two loci defined by markers CI17-701 and CI17-730 at 17q21.3, which are 2.4 cM apart. This segment overlaps the region that includes the putative gene for hereditary breast and ovarian carcinomas. The results suggest that at least two tumor suppressor genes associated with sporadic ovarian and breast cancers are present on chromosome 17q and that one of them may be the same gene that is responsible for the hereditary form.

Adenocarcinoma↗
PubMed1993

Human ryudocan core protein: molecular cloning and characterization of the cDNA, and chromosomal localization of the gene.

We have isolated a series of overlapping cDNA clones encoding a 2,628 bp transcript, which potentially codes for a 198 amino acid protein with predicted molecular mass of 21,641 daltons, for the human ryudocan core protein. The deduced core proteins of the human and the rat ryudocan have high structural conservation, particularly in the NH2 and COOH terminus regions of the putative mature core protein, including the combined transmembrane/cytoplasmic domains with conserved positions of all 4 tyrosine groups and 3 conserved glycosaminoglycan chain attachment regions, which might serve important roles for biological function of ryudocan. A major 2.7 kb transcript was detected in all tissues tested, with relatively high levels of expression observed in mRNA from lung, liver, skeletal muscle and kidney. A minor 1.9 kb transcript was also observed in some of tissues, which would be caused by alternative polyadenylation. Human ryudocan gene has been localized on the chromosome 20q12 by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed1993

Mapping the breakpoint of a constitutional translocation on chromosome 22 in a patient with NF2.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterized by development of bilateral acoustic neurinomas and increased incidence of meningiomas. Frequent losses of I allele of chromosome 22 in neurinomas and meningiomas has indicated that the gene responsible for NF2 functions as a tumor suppressor. Although the NF2 gene has been mapped within a 13 cM region between D22S1 and D22S28 by linkage analysis, its location with respect to D22S15 is uncertain. We previously reported an NF2 patient with a constitutional balanced translocation t(4;22)(q12;q12.2); the NF2 gene is probably disrupted at the breakpoint. To define the location of this breakpoint on chromosome 22, we performed fluorescence in situ hybridization (FISH) with DNA markers in the NF2 region and determined the physical order of 5 loci: D22S1-NF2-LIF-D22S15-D22S32.

Base Sequence↗
PubMed1993

High-resolution cytogenetic mapping of 342 new cosmid markers including 43 RFLP markers on human chromosome 17 by fluorescence in situ hybridization.

We have constructed a high-resolution cytogenetic map of human chromosome 17 with 342 cosmid markers, each newly isolated from a cosmid library constructed from a human-mouse hybrid cell line containing a single human chromosome 17. Direct mapping on R- and/or G-banded (pro)metaphase chromosomes by fluorescence in situ hybridization localized these markers throughout the chromosome, although density was highest in the R-band-dominant regions of 17p13, 17p11.2, 17q11.2-q12, 17q21.3, 17q23, and 17q25. By screening some of the cosmid clones, we identified 71 polymorphic systems with 43 markers; 11 of these are VNTRs. As our high-resolution cytogenetic map contains a large number of markers, it can provide useful landmarks for a contig map of chromosome 17. Furthermore, the map will contribute to positional cloning of aberrant genes responsible for inherited diseases such as Miller-Dieker syndrome (MDS), Smith-Magenis syndrome (SMS), and familial early-onset breast cancer, as well as putative tumor suppressor genes on this chromosome.

Animals↗
PubMed1993

Isolation of region-specific cosmids by hybridization with microdissection clones from human chromosome 10q11.1-q21.1.

A region-specific plasmid library composed of 20,000 recombinants was constructed by microdissection of human chromosome 10 (10q11.2-q21.1) and subsequent amplification with the primer-linker method of polymerase chain reaction (PCR). Hybridization with total human DNA showed that 32 of 217 microclones studied contained highly repetitive sequences. Further analysis of the remaining 185 microclones proved that 43 microclones, each having an insert longer than 200 bp, contained unique sequences of human chromosome 10 origin. Twenty-five microclones randomly selected from the 43 were used directly as probes to isolate corresponding cosmid clones, resulting in 32 cosmids corresponding to 14 microclones. Of the 25 cosmids that could be mapped by fluorescence in situ hybridization, 24 proved to originate from the microdissected or adjacent region (10p11.2-q22.3) and 1 from a rather distal region (10q24.3-q25.1). In addition, 15 of the 32 cosmids revealed restriction fragment length polymorphisms, including 1 with a variable number of tandem repeats marker. The microdissection library and the obtained cosmids are valuable resources for constructing high-resolution physical and linkage maps of the pericentromeric region of chromosome 10, where the gene predisposing to multiple endocrine neoplasia type 2A (MEN2A) has been mapped.

Base Sequence↗
PubMed1993

Chromosomal localization and cDNA sequence of human BTEB, a GC box binding protein.

Human BTEB cDNA clones have been isolated, sequenced, and the corresponding gene has been assigned to human chromosome 9, region q13, by fluorescent in situ hybridization and DNA blot analysis using DNAs from hybrid cell clones containing a single human chromosome. The cDNA clone encodes a polypeptide of 244 amino acids whose sequence shows a high sequence similarity with the rat BTEB (98% amino acid identity).

Amino Acid Sequence↗
PubMed1993

Chromosomal location and structure of amplicons in two human cell lines with coamplification of c-myc and Ki-ras oncogenes.

Gene amplification is a major mechanism through which oncogenes and genes responsible for drug resistance are overexpressed in neoplastic cells, and several models for structure of amplified units (amplicons) are postulated. In order to identify consistent changes associated with oncogene amplification, we analyzed chromosomal location and physical distance of amplicons of two independent human cell lines that have coamplified c-myc and Ki-ras oncogenes. In one cell line, KHC287, amplified c-myc genes were localized in two chromosomes and Ki-ras in three chromosomes. One marker chromosome was almost entirely encompassed by both amplified genes. In the other cell line, Lu-65, both of the amplified genes shared the same locus, on chromosome 12q+. The two genes, however, are more than 1500 kb apart in both cell lines. The above findings indicate that two different amplified genes became associated on one chromosome in two independent cell lines. This suggests that a common mechanism is associated with chromosomal rearrangements affecting different amplified genes.

Chromosome Mapping↗
PubMed1993

A novel metalloprotease/disintegrin-like gene at 17q21.3 is somatically rearranged in two primary breast cancers.

From chromosomal region 17q21.3, where a tumour suppressor gene(s) for breast and ovarian cancers is thought to be present, we have isolated a novel gene from a cosmid clone that revealed somatic rearrangements in two breast cancers. The gene (MDC) encodes a 524-amino acid metalloprotease-like, disintegrin-like and cysteine-rich protein with sequence similarity to members of the snake-venom metalloprotease/disintegrin family and guinea-pig sperm-surface protein PH-30. These proteins have been implicated in cell-cell or cell-extracellular matrix interactions. Rearrangements in both tumours involve multiple exons and disrupt the coding region of the new MDC.

Amino Acid Sequence↗
PubMed1993

Chromosomal assignment of the gene for protein tyrosine phosphatase HPTP delta.

Protein tyrosine phosphatase (PTP) negatively regulates the effect of protein tyrosine kinases and is implicated in the regulation of a variety of biological phenomena such as cell activation, differentiation and neoplastic transformation. To gain insight into the role of PTPs, we cloned the human receptor-type PTP gene and assigned the chromosome harboring the gene for HPTP delta by using DNAs from human-mouse hybrid cell lines and by fluorescence in situ hybridization. The results clearly demonstrated that HPTP delta gene maps to human chromosome 9p24.

Animals↗
PubMed1993

[Detection of minimal residual clone after sex-mismatched bone marrow transplantation by fluorescent in situ hybridization].

In our previous paper we reported that fluorescent in situ hybridization (FISH) using DYZ1 and DXZ1 was a highly reproducible technique and cellular chimerism consisting of cells of male and female origins could be detected in the order of 0.1%. In the present study FISH was applied to detect minimal residual clones (MRC) in 10 patients with a variety of leukemias who received sex-mismatched bone marrow transplantation (BMT). In 9 patients who had no signs of recurrence, serial FISHs performed on each patient revealed the presence of 0.1 to 3.2% recipient residual clone. On the other hand, in the remaining one patient 10.6% and 16.9% of MRC were found by FISH performed 6 and 10 months after BMT. Immediately thereafter, this patient was diagnosed as in relapse by bone marrow examination.

Adolescent↗
PubMed1992

The RCK gene associated with t(11;14) translocation is distinct from the MLL/ALL-1 gene with t(4;11) and t(11;19) translocations.

We previously demonstrated that the 11q23 breakpoint region, designated the RCK locus, of the RC-K8 B-lymphoma cell line with t(11;14)(q23;q32) is centromeric to PBGD, while breakpoints of infantile leukemia cell lines with t(11;19)(q23;p13) are detectable by pulsed-field gel electrophoresis with the CD3D probe. In the present study, using a probe within 1.0 kilobase of the t(11;14) breakpoint, we isolated a partial complementary DNA clone for the putative RCK gene, which detects a 7.5-kilobase mRNA. Sequence analysis predicted a novel protein of 472 amino acids which demonstrated sequence homology to a translation initiation factor/helicase family. We also isolated a phage clone from the CD3D/G yeast artificial chromosome clone (yB22B2) which detects 11- and 12-kilobase mRNAs, most likely for the MLL/ALL-1 gene associated t(4;11)(q21;q23) and t(11;19)(q23;p13) translocations. By pulsed-field gel electrophoresis after NotI digestion, this recombinant clone is on a 96-kilobase fragment, while RCK and PBGD probes are on a more telomeric 690-kilobase NotI fragment. These results, altogether, suggested that two different genes, RCK and MLL/ALL-1, are associated with 11q23 translocation of hematopoietic tumors.

Amino Acid Sequence↗
PubMed1992

Structure of the gene for human transglutaminase 1.

Transglutaminase 1 (TG1) is an enzyme that is expressed and activated during terminal differentiation of keratinocytes and synthesizes cornified envelope by a cross-linking reaction. The gene encoding human TG1 was isolated from human genomic DNA and characterized. It spans 14.3 kilobase pairs and is composed of 15 exons. All exon-intron junctional sequences conformed to the canonical GT-AG rule. The translation start was located in the second exon. The active site Cys residue of the enzyme was in exon 7. The coding sequence for human TG1 was comprised of 2454 nucleotides identical with the published human TG1-cDNA sequence (Yamanishi, K., Liew, F.-M., Konishi, K., Yasuno, H., Doi, H., Hirano, J., and Fukushima, S. (1991) Biochem. Biophys. Res. Commun. 175, 906-913). The sizes of exons from 3 to 14 were markedly conserved between the genes for the human TG1 and factor XIIIa, another member of the transglutaminase family. The one major and two minor transcription initiation sites of the TG1 gene were determined by primer extension. The 5'-flanking region of the human TG1 gene showed features of a housekeeping gene and contained potential regulatory motifs, including elements found in keratinocyte-related genes. The chromosome sublocalization of the TG1 gene was assigned to 14q11.2.

Amino Acid Sequence↗
PubMed1992

Structure of the human ferrochelatase gene. Exon/intron gene organization and location of the gene to chromosome 18.

We have determined the structure of the human ferrochelatase gene after isolation and characterization of lambda phage clones mapping discrete regions of the cDNA. This gene was assigned to human chromosome 18 at region q21.3, by fluorescent in situ hybridization. The gene contains a total of 11 exons and has a minimum size of about 45 kb. The exon/intron boundary sequences conform to consensus acceptor (GTn) and donor (nAG) sequences, and the exons in the gene appear to encode functional protein domains. A major site of the transcription initiation, determined by S1 nuclease mapping, was assigned to an adenine base 89 bases upstream from the adenine base of the translation initiation ATG. The promoter region contains a potential binding site for Sp1, NF-E2 and erythroid-specific transcriptional factor GATA-1, but not a typical TATAA or CCAAT sequence. Analysis of primer extension showed that the transcription starts at the same position between hepatoma HepG2 and erythroleukemia K562 cell mRNA, thereby suggesting that there can be a single transcript in erythroid and non-erythroid cells.

Base Sequence↗
PubMed1992

Assignment of the human cytochrome P-450 nifedipine oxidase gene (CYP3A4) to chromosome 7 at band q22.1 by fluorescence in situ hybridization.

We have used a full length cDNA clone (2.2 kb) for the human cytochrome P-450 nifedipine oxidase (CYP3A4) enzyme as a probe to determine its chromosome localization by fluorescence in situ hybridization. CYP3A4 was mapped on R-banded human prometaphase chromosomes, and the precise localization of CYP3A4 on chromosome 7 was further confirmed by a delineation of G-banded pattern on the same prometaphase chromosomes through a combination of UV-filter. We assigned CYP3A4 to chromosome 7 at q22.1.

Cells, Cultured↗
PubMed1992

Detection of an i(17q) chromosome by fluorescent in situ hybridization with a chromosome 17 alpha satellite DNA probe.

An isochromosome for the long arm of chromosome 17,i(17q), is frequently found as an additional chromosome aberration to the Ph with advanced disease in the chronic myelocytic leukemia (CML). We studied an i(17q) in blood samples from two patients with CML in blast crisis with a biotinylated chromosome 17 specific alpha satellite deoxyribonucleic acid probe. G-banded karyotypes of these patients showed a dicentric i(17q), dic(17)(p11.2). Fluorescence in situ hybridization (FISH) delineated one normal chromosome 17 and one i(17q) among metaphase chromosomes; the latter showed a dicentric pattern. In most interphase nuclei of both patients, two fluorescence spots were observed. In some interphase nuclei, including mature neutrophils, the dicentric chromosome was discernible by its size and shape of the fluorescent spots. Three fluorescent spots were observed in a small proportion of interphase cells, and existence of a subclone with two normal chromosome 17 and an i(17q) was confirmed by examining a large number of metaphase plates. The results of FISH provided us with information of numerical and structural aberrations of chromosome 17 in interphase cells.

Blast Crisis↗